Ball bearing assembly



Sept. 13, 1966 M. BUSHI 3,272,575

BALL BEARING ASSEMBLY Original Filed Feb. 21. 1962 INVENTOR.

MICHAEL BUSHI BY fimfirgw J 0M ATTORNEYS United States Patent 3 Claims. (Cl. 308195) This application is a division of my earlier filed copending application Ser. No. 174,730, filed Feb. 21, 1962, now U.S. Patent No. 3,137,920.

The present invention relates generally as indicated to a ball bearing assembly and more particularly to a twopiece ball bearing having a full complement of balls.

Hitherto, ball bearings of the type having a full complement of balls between the race members have comprised at least one split race member including means for holding the split parts together. It is also known in the art to provide inner and outer race members of which the inner member has an outside diameter such that the full complement of balls may be positioned in the raceway of the outer member, whereupon said inner member is expanded in diameter to bring the inner raceway into engagement with the balls to retain them between said members. As apparent, the making of the last-mentioned type of two-piece ball bearing entails radial expansion of the inner race member and, as a consequence, the stretching of the metal makes it difiicult to match the curvature of the inner raceway with the radii of the ball-s.

Accordingly, it is a principal object of this invention to provide a two-piece ball bearing assembly in which one of the race members is subjected to compressive forces to secure conformance of its raceway with the radii of the balls.

Other objects and advantages of the present invention will become apparent as the following description proceed-s.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a top plan view of a two-piece ball bearing made in accordance with this invention;

FIG. 2 is a cross-section view along line 2-2, FIG. 1;

FIG. 3 is a much enlarged radial cross-section view of the FIG. 2 bearing prior to final assembly of the parts;

FIG. 4 is a view similar to FIG. 3, except showing the inner race member deformed to form a complete ball bearing assembly;

FIGS. 5 and 6 are enlarged radial cross-section views similar to FIGS. 3 and 4, except showing a ball bearing assembly wherein the outer race member is deformed to provide the final ball bearing assembly;

FIGS. 7 and 8 also are enlarged radial cross-sections similar to FIGS. 3 and 4 and 5 and 6, except showing yet another ball bearing embodying the present invention; and

FIG. 9 is a cross-section view of a two-piece stud-type ball bearing embodying the present invention.

Referring now in detail to the drawings, and first to FIGS. 1 to 4, the bearing 1 there shown comprises an outer race member 2 having an internal groove (or outer raceway) 3 preferably of radius corresponding to the radii of the balls 4. The inner race member 5 fabricated as of dead soft, hardenable steel is formed with a curved shoulder 6 which is of radius slightly greater than the radii of the balls. For example, the radius of the surface 6 will generally be .015 larger in radius than the radii of ice the balls 4. The cylindrical portion 7 of the inner memher is preferably of outside diameter .010" to .015" less than the desired final root diameter of the inner raceway 8 of the finished bearing of FIGS. 1, 2 and 4.

In order to complete the bearing from its FIG. 3 condition, the outer and inner race members 2 and 5 are supported on die blocks 9 and 10, whereupon a curling punch 11 is forced axially into the upper end of the inner race member 5 to not only radially expand or flare out the upper end thereof, but also to apply substantial axial compressive force thereon to cause the resulting raceway 8 to conform to the balls 4. This curling or flaring operation locks the inner and outer race members 5 and 2 together with a full complement of balls 4 therebetween, said members having raceways 8 and 3 matching the radii of the balls 4.

In bearings of this type the space between the raceways contains a full complement of balls 4 with only a small clearance of say, between the first ball and the last ball when they are crowded together in contact with one another.

In mass production of bearings of this type, the race member 5 and die block 10 will be pressed downward against a spring (not shown) for loading the required number of balls 4 between the race members 2 and 5, whereupon the assembly of FIG. 3 is transferred to a curling station whereat, while both die blocks 9 and 10 are solidly backed up, the punch 11 is forced downward to curl out the portion 7 and to radially deform the race member 5 so that its initially curved shoulder 6 and its initially cylindrical surface of portion 7 define the raceway 8 that matches the balls 4 in the completed bearing. Thereafter, the bearing 1 is heat treated, preferably in an inert atmosphere.

The punch 11 has an annular lip 12 which predetermines the extent of curling and traps the metal for application of substantial compressive force to secure conformance of the raceway 8 with the balls 4. It has been found essential to round the outer corner 13 (.015 to .030" radius) of the tubular portion 7 in order to prevent splitting during the curling operation. The inner corner may have a .005" radius.

It has been discovered that the raceway 8 will have a true radius matching the ball radius within close limits only if the punch 11 has a radius R approximately equal to the radius of the balls 4. In this way, the metal is trapped and subjected to axial compression of such magnitude that the portion 7 does not split and is swaged or deformed to match the balls 4 without Brinelling of the balls in the finished raceway 8. Attempts simply to flare the portion 7 with a flaring tool having a flaring surface struck from the center of the balls 4 and having a radius equal to that of the balls 4 plus the wall thickness of portion 7 have resulted in splitting and in frusto-conical raceways 8 which do not match the balls 4.

The bearing 14 shown in FIGS. 5 and 6 is generally the same as that of FIGS. 1 to 4, except that the outer race member 15 is curled inwardly and is subjected to axial compressive force by the punch 16 to form the completed bearing.

The bearing 14 comprises an inner race member 17 formed with the raceway 18 for the balls 19, and the outer race member 15 which, when curled in and compressed axially, has a raceway 20 matching the balls 19. As in FIG. 3, the race member 15 has a curved shoulder 21 of radius slightly greater than that of the balls 19. The punch 16 preferably has a curved surface 22 of radius approximately equal to that of the balls 19.

The bearing 23 of FIGS. 7 and 8 corresponds generally to bearing 1 of FIGS. 1 to 4, except that the up per end portion 24 of the inner race member 25 is initially of frusto-conical form, whereupon the tapered punch 26 is effective to radially outwardly deform the frustoconical portion 24 to cylindrical form to cause the raceway 27 to match the balls 28. The outer race member 29 has a raceway 30 which optionally may be of V-shaped or curved, as desired.

The bearing 31 of FIG. 9 is of the stud-type having an outer race 32, an inner race 33 (curled as in FIG. 4), and a full complement of balls 34 therebetween. The inner race 33 has an integral stud 35 for riveting to a suitable mounting member.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. A two-part ball bearing assembly having inner and outer race members, with one of said inner and outer race members having a preformed raceway having a radius approximately equal to that of said balls, the other of said inner and outer race members being in its preformed state generally cylindrical and formed with an annular ball-supporting shoulder and in its completely formed state axially compressed to form a raceway radius approximately equal to the radius of said balls to closely conform to the surface thereof, said other race member having a top exterior surface axially compressed to form a radius approximately equal to the radius of said balls.

2. The bearing assembly of claim 1 wherein the preformed annular upper edge of said generally cylindrical race member adjacent said balls is rounded to prevent splitting of said edge during deformation thereof.

3. The bearing assembly of claim 1 wherein the radius of said annular shoulder is slightly greater than the radius of said balls.

References Cited by the Examiner UNITED STATES PATENTS 1,189,262 7/1916 Krantz 308195 2,350,228 6/1944 I-Ianes 308-6 2,998,636 9/1961 Spence et a1 29-1484 3,013,327 12/1961 Spence 308195 FOREIGN PATENTS 502,554 4/1951 Belgium. 327,050 3/ 1930 Great Britain.

DAVID J. WILLIAMOWSKY, Primary Examiner.

FRANK SUSKO, Examiner. 

1. A TWO-PART BALL BEARING ASSEMBLY HAVING INNER AND OUTER RACE MEMBERS, WITH ONE OF SAID INNER AND OUTER RACE MEMBERS HAVING A PREFORMED RACEWAY HAVING A RADIUS APPROXIMATELY EQUAL TO THAT OF SAID BALLS, THE OTHER OF SAID INNER AND OUTER RACE MEMBERS BEING IN ITS PREFORMED STATE GENERALLY CYLINDRICAL AND FORMED WITH AN ANNULAR BALL-SUPPORTING SHOULDER AND IN ITS COMPLETELY FORMED STATE AXIALLY COMPRESSED TO FORM A RACEWAY RADIUS APPROXIMATELY EQUAL TO THE RADIUS OF SAID BALLS TO CLOSELY CONFORM TO THE SURFACE THEREOF, SAID OTHER RACE MEMBER HAVING A TOP EXTERIOR SURFACE AXIALLY COMPRESSED TO FORM A RADIUS APPROXIMATELY EQUAL TO THE RADIUS OF SAID BALLS. 